A paper in this week’s Nature predicts that, rather than warming, North Atlantic sea surface temperatures may actually decrease slightly in the next decade. What’s more, the paper suggests global surface temperatures may not actually increase either.
Has global warming stopped? Is this a nail in Al Gore’s coffin?
Despite headlines such as ‘Doubt is cast over global warming’ and ‘Global warming could stop NATURALLY for ten years, say scientists’ that is not what this paper is about.
What this new paper by Noel Keenlyside, of the Leibniz Institute of Marine Sciences in Germany, sets out to do is incorporate data on short term variations in climate into our models of climate change. By doing this they push us into the arena of creating shorter term predictions, in this case of the next decade.
In a “News and Views” commentary on the piece in the same issue of Nature Richard Wood explains:
Keenlyside and colleagues’ model uses a very simple ocean initialization method in which they add heat to or remove it from the ocean surface until sea surface temperatures across the globe are close to observed values. They use their model to produce a set of retrospective ‘forecasts’ starting from earlier states, which they test against what actually happened. Their system produces refined temperature predictions a decade ahead for large parts of Europe and North America.
As Woods points out, colleagues of his at the Hadley Centre in the UK published a similar sort of prediction research of a similar sort, though rather different in approach and with significantly different predictions, in Science last year, as we reported at the time. Combining real world data and modelling this way has only recently become possible.
The new model predicts North Atlantic, European and North American sea surface temperatures will cool slightly; tropical Pacific temperatures will likely be almost unchanged and global temperatures will probably be offset by this variation.
This does not mean we don’t need to worry about global warming. “The natural variations change climate on this timescale and policymakers may either think mitigation is working or that there is no global warming at all,” says Keenlyside (Reuters).
As the NY Times’s Andrew Revkin notes on his blog:
Whether their prediction of a plateau for warming for a decade in North America and Europe is correct or not, their research may signal a shift that many climate researchers have been calling for for awhile now — toward service-oriented climate science …
The NY Times wraps up its main piece with a useful quote from Kevin Trenberth, of the US National Center for Atmospheric Research: “Too many think global warming means monotonic relentless warming everywhere year after year. It does not happen that way.”
Not everyone is happy though. Here’s the always-worth-listening-to Roger Pielke Jr on his Prometheus blog:
I am sure that this is an excellent paper by world class scientists. But when I look at the broader significance of the paper what I see is that there is in fact nothing that can be observed in the climate system that would be inconsistent with climate model predictions. If global cooling over the next few decades is consistent with model predictions, then so too is pretty much anything and everything under the sun.
Image: NASA Glenn Research Center (NASA–GRC)
Cross posted by Daniel Cressey on The Great Beyond